Obsidian is a personal knowledge base and note-taking application that operates on markdown files.

[3][4][5] Obsidian allows users to make internal links for notes and then to visualize the connections as a graph.

[15] Obsidian is built on the cross-platform Electron framework, allowing for the application to run on desktop operating systems like Windows, Linux, and macOS.

While Obsidian is free for non-commercial purposes and does not charge users to access any core features, the developers have launched and integrated various premium services into the application for additional needs[3][16].

Vaults that are published with the service are typically formatted similarly to the application, with a graph view provided for links between pages.

[21] The service is positioned as an alternative to do-it-yourself solutions both inside and outside of the application, which typically require some amount of manual configuration.